Certain aspects of the (linear and nonlinear) stability of sheared relativistic (slab) jets are analyzed. The linear problem has been solved for a wide range of jet models well inside the ultrarelativistic domain (flow Lorentz factors up to 20, specific internal energies approximately 60c2). As a distinct feature of our work, we have combined the analytical linear approach with high-resolution relativistic hydrodynamical simulations, which has allowed us (i) to identify, in the linear regime, resonant modes specific to the relativistic shear layer, (ii) to confirm the result of the linear analysis with numerical simulations, and (iii) more interestingly, to follow the instability development through the nonlinear regime. We find that very-high-order reflection modes with dominant growth rates can modify the global, long-term stability of the relativistic flow. We discuss the dependence of these resonant modes on the jet flow Lorentz factor and specific internal energy and on the shear-layer thickness. The results could have potential applications in the field of extragalactic relativistic jets.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1103/PhysRevE.75.056312 | DOI Listing |
Phys Rev E
November 2024
Department of Physics "A. Pontremoli," University of Milan, via Celoria 16, 20133 Milan, Italy and Institute of Theoretical Physics, University of Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany.
The shear viscosity is a fundamental transport property of matter. Here we derive a general theory of the viscosity of gases based on the relativistic Langevin equation (deduced from a relativistic Lagrangian) and nonaffine linear response theory. The proposed relativistic theory is able to recover the viscosity of nonrelativistic classical gases, with all its key dependencies on mass, temperature, particle diameter, and Boltzmann constant, in the limit of Lorentz factor γ=1.
View Article and Find Full Text PDFPhys Rev Lett
August 2024
Illinois Center for Advanced Studies of the Universe Department of Physics, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA.
We derive necessary and sufficient conditions under which a large class of relativistic generalizations of Braginskii's magnetohydrodynamics with shear, bulk, and heat diffusion effects is causal and strongly hyperbolic in the fully nonlinear regime in curved spacetime. We find that causality severely constrains the size of nonideal effects and the onset of kinetic instabilities. Our results are crucial for assessing the regime of validity of fluid dynamical simulations of plasmas near supermassive black holes.
View Article and Find Full Text PDFEntropy (Basel)
July 2024
Mathematical Sciences and STAG Research Centre, University of Southampton, Southampton SO17 1BJ, UK.
We develop an action principle for producing a single-fluid two-constituent system with dissipation in general relativity. The two constituents in the model are particles and entropy. The particle flux creation rate is taken to be zero, while the entropy creation rate is non-zero.
View Article and Find Full Text PDFPhys Rev Lett
August 2024
Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742, USA.
We show that the dynamics of high-intensity laser pulses undergoing self-focused propagation in a nonlinear medium can be understood in terms of the topological constraints imposed by the formation and evolution of spatiotemporal optical vortices (STOVs). STOVs are born from pointlike phase defects on the sides of the pulse nucleated by spatiotemporal phase shear. These defects grow into closed loops of spatiotemporal vorticity that initially exclude the pulse propagation axis, but then reconnect to form a pair of toroidal vortex rings that wrap around it.
View Article and Find Full Text PDFPhys Rev Lett
February 2024
Department of Physics and Astronomy, Wayne State University, Detroit, Michigan 48201, USA.
This work presents the first Bayesian inference study of the (3+1)D dynamics of relativistic heavy-ion collisions and quark-gluon plasma viscosities using an event-by-event (3+1)D hydrodynamics+hadronic transport theoretical framework and data from the Relativistic Heavy Ion Collider Beam energy scan program. Robust constraints on initial state nuclear stopping and the baryon chemical potential-dependent shear viscosity of the produced quantum chromodynamic (QCD) matter are obtained. The specific bulk viscosity of the QCD matter is found to exhibit a preferred maximum around sqrt[s_{NN}]=19.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!